[Populus arizonica Sarg., morePopulus arizonica var. jonesi Sarg., Populus arizonica var. jonesii Sarg., Populus canadensis var. fremontii (S. Wats.) Kuntze, Populus fremontii var. arizonica (Sarg.) Jepson, Populus fremontii var. macdougalii (Rose) Jepson, Populus fremontii var. macrodisca Sarg., Populus fremontii var. pubescens Sarg., Populus fremontii var. thornberi Sarg., Populus fremontii var. toumeyi Sarg., Populus macdougalii Rose]
Plants to 30 m. Branchlets, leaf blades, and petioles glabrous or glabrate to densely hairy, hairs whitish. Neoformed leaves: blade broadly triangular-ovate, usually about as wide as long, rarely wider, base truncate or cordate, apex short-acuminate. Capsules (6-)7.5-11 mm.
Flowering Feb-May; fruiting Mar-Jun. Floodplains, canyons, springs, other moist places; (-60-)0-1500 (-2200) m; Ariz., Calif., Idaho, Nev., N.Mex., Utah; Mexico (Baja California, Baja California Sur, Sonora).
Subspecies fremontii is the common cottonwood of southwestern North America west of the Continental Divide. It intergrades with subsp. mesetae along a line from southeastern Arizona south along the border between Chihuahua and Sonora.
LEAVES: broadly triangular-ovate, usually about as wide as long. NOTES: See also parent taxon. Floodplains, canyons, springs and other moist places: all cos. except Apache; 8-2200 m (25-7300 ft); Feb-Apr (fr. Mar-May); w of the continental divide, n CA and n UT to Baja C. Sur and c Son., Mex. REFERENCES: Eckenwalder, James E. 1992. Salicaceae. Ariz.-Nev. Acad. Sci. 26(1)2.